Fix for bug #14304: auto_increment field incorrect set from within stored procedure (insert select).


sql/sp_head.cc:
  Fix for bug #14304: auto_increment field incorrect set from within stored procedure (insert select).
  - call thd->cleanup_after_query() to clean next_insert_id.
sql/sql_class.cc:
  Fix for bug #14304: auto_increment field incorrect set from within stored procedure (insert select).
  - save/restore clear_next_insert_id
sql/sql_class.h:
  Fix for bug #14304: auto_increment field incorrect set from within stored procedure (insert select).
  - clear_next_insert_id added